Stathmin overexpression in 293 cells affects signal transduction and cell growth.
Stathmin is a ubiquitous cytoplasmic protein whose phosphorylation state changes markedly in response to extracellular signals, and during the cell cycle. To clarify the function of stathmin, its four phosphorylation sites were mutated to either alanines (4A-stathmin) or glutamates (4E-stathmin). In transfected cells, 4A-stathmin caused a strong G2/M block and also inhibited the responsiveness of a co-transfected fos promoter/ luciferase reporter plasmid to serum stimulation, whereas wild type and 4E-stathmin had relatively minor effects. These results support the idea that stathmin plays a role in multiple cellular processes and indicate that the regulation of the phosphorylation state of stathmin is likely to determine its action.
Lawler
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S
INSERM U440, Paris, France.
Gavet
O
O
Rich
T
T
Sobel
A
A
D000409:Alanine; D019943:Amino Acid Substitution; D002453:Cell Cycle / Q000502:physiology*; D002455:Cell Division; D002460:Cell Line; D005434:Flow Cytometry; D017930:Genes, Reporter; D018698:Glutamic Acid; D006801:Humans; D007668:Kidney; D007700:Kinetics; D008156:Luciferases / Q000096:biosynthesis; D008868:Microtubule Proteins; D016297:Mutagenesis, Site-Directed; D010750:Phosphoproteins / Q000096:biosynthesis / Q000502:physiology*; D010766:Phosphorylation; D011401:Promoter Regions, Genetic; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D015398:Signal Transduction; D050777:Stathmin; D014162:Transfection
D008868:Microtubule Proteins; D010750:Phosphoproteins; D011993:Recombinant Fusion Proteins; C493995:STMN1 protein, human; D050777:Stathmin; D018698:Glutamic Acid; D008156:Luciferases; D000409:Alanine